In the field of light-sensitive materials, techniques of rapid processing have recently been progressing very fast. Achievement of rapid exposure requires reduction of exposure time (increase of photographic speed), transfer properties in an exposure apparatus, e.g., cameras and scanners, toughness on handling, and the like. Speeding up of development is achieved by high temperature rapid development by using an automatic developing machine, and achievement of reduction of development time requires a light-sensitive material which has high development rate and can be dried in a reduced time after being washed with water.
In X-ray films, light-sensitive materials for microphotography, and negative films for general photography, improvement in covering power (i.e., optical density per unit silver amount) is essential for accomplishing an increase of photographic speed. It is known that a covering power can be improved by reducing the amount of gelatin as disclosed, e.g., in JP-A-61-116347 and JP-A-57-182732 (the term "JP-A" as used herein means an "unexamined published Japanese patent application"). However, reduction of gelatin amount relative to silver amount tends to cause abrasion marks, i.e., blackening of scratches of light-sensitive materials due to rubbing with each other.
Where tabular silver halide grains having a high aspect ratio are used for the purpose of increasing photographic speed, the light-sensitive materials tend to suffer from stress marks due to abrasion or bending during handling before development processing.
Further, reduction of the amount of a binder for the purpose of improving development rate and increasing drying speed after washing easily causes deterioration in graininess or an increase of stress marks on handling.
It has been proposed to improve both abrasion resistance and covering power by incorporating a water-soluble polyester into light-sensitive materials as disclosed in JP-A-64-29834. This technique, however, does not bring about a complete solution to the above-described problems, still leaving a need of further improvements.
In the field of photomechanical process, systems of stably and rapidly forming a ultra-high contrast negative image having a gamma exceeding 10 while eliminating instability observed in conventional image formation systems using lith development have been developed as described in U.S. Pat. Nos. 4,166,742, 4,168,977, 4,221,857, 4,224,401, 4,243,739, 4,272,606, and 4,311,781. According to these systems, a hydrazine compound is used to achieve an increased sensitivity and an increased contrast, while making it possible to greatly speed up processing (development time: 20 to 30 seconds) over the lith development systems (development time: 60 to 100 seconds). Nevertheless, in spite of the high sensitivity and ultra-high contrast achieved, the systems involve a disadvantage that the light-sensitive materials tend to suffer from rather amplified abrasion marks, stress marks, etc.
JP-A-62-21143 and JP-A-56-1936 propose an improvement to be added to the ultra-high contrast image formation systems using a hydrazine compound, in which hydroquinone or a substituted polyhydroxybenzene is used to improve resistance to stress marks. Further, JP-A-54-40629 discloses use of a substituted hydroquinone, and especially hydroquinone substituted with a thio group for the improvement of sensitivity and contrast. All these hydroquinone derivatives are different from the compounds according to the present invention.